I have some issue in passing a FTP string into QUrl:
std::cout << QUrl::fromUserInput("ftp://user#host.com:password#ftphost:21/path/file.ext").toString().toStdString().c_str() << std::endl;
Is always resulting in
http://ftp//user#host.com:password#ftphost:21/path/file.ext
which is obviously wrong. What's the problem with the above FTP Url? Or is that a known issue within Qt4?
I am working on Linux, using Qt 4.8.1.
Even following code
if(QUrl("ftp://user#host.com:password#ftphost:21/path/file.ext").isValid())
std::cout << "is valid" << std::endl;
else
std::cout << "is not valid" << std::endl;
Is resulting in "is not valid"
Thanks in advance
You need manually replace # in username with %40. That's what QUrl does internally if QUrl::setUserName() is called with user#domain.tld.
Related
I am on a Windows Server which is in the same network as the Server with the computer name service.
I got this simple code which tries to list the content
QFileInfoList fiList = QDir("\\service\\Documents").entryInfoList(QDir::Files);
qDebug() << "sizeof filist: " << fiList.size();
for (const QFileInfo& fi : fiList)
{
qDebug() << fi.absoluteFilePath();
}
The output is the following:
sizeof filist: 0
I make sure that the folder is shared on the network by checking the properties and also using the windows explorer. I can access the folder via Windows Explorer.
Is the functionality I am trying to achieve not possible with QDir?
It turns out there are 2 backslashes more needed because \ needs to be escaped.
So the right code would be:
QFileInfoList fiList = QDir("\\\\service\\Documents").entryInfoList(QDir::Files);
qDebug() << "sizeof filist: " << fiList.size();
for (const QFileInfo& fi : fiList)
{
qDebug() << fi.absoluteFilePath();
}
I used Qt on MAC OS and try to retrieve the metadata of media. So i took the Qt's Media Player Example (Qt 5.8.0) and modified a little bit:
Instead of:
connect(controls, SIGNAL(play()), player, SLOT(play()));
i used:
connect(controls, &PlayerControls::play, player,
[this]{
qDebug() << player->isMetaDataAvailable();
qDebug() << player->metaData(QMediaMetaData::Size);
player->play();
qDebug() << player->isMetaDataAvailable();
qDebug() << player->metaData(QMediaMetaData::Resolution);
});
The results are:
false
QVariant(Invalid)
false
QVariant(Invalid)
1st question: why is the metadata not available even after the media started playing?
2nd question: i added some codes in the destructor:
Player::~Player()
{
qDebug() << player->isMetaDataAvailable();
qDebug() << player->metaData(QMediaMetaData::Duration);
}
Now the metadata is available, but no data is returned:
true
QVariant(Invalid)
Can anyone help me please?
Update Question 1:
Instead of
connect(controls, SIGNAL(pause()), player, SLOT(pause()));
i used:
connect(controls, &PlayerControls::pause, player,
[this]{
qDebug() << player->isMetaDataAvailable();
qDebug() << player->metaData(QMediaMetaData::Resolution);
});
And after about 3-5 seconds of playing, the metadata is already available, but it also returns nothing:
true
QVariant(Invalid)
This is not the exact answer for your question but this may help you. You can check which metadata available with this code:
QMetaDataReaderControl *c = qobject_cast<QMetaDataReaderControl*>(player_->service()->requestControl(QMetaDataReaderControl_iid));
if(c) {
connect(c, &QMetaDataReaderControl::metaDataAvailableChanged, [c](bool) {
qDebug() << c->availableMetaData();
});
}
I', not sure, but I think that qDebug cannot handle QVariant, you should use for example:
qDebug() << (player->metaData(QMediaMetaData::Title)).toString();
I have following chunk of Qt code:
if(this->ueCommunicationsSocket()->bind(QHostAddress(data[0].toString()),
static_cast<quint16>(data[1].toInt())),
QAbstractSocket::ShareAddress)
{
qDebug() << Q_FUNC_INFO
<< "TCP socket bind succesfull";
}
else
{
qDebug() << Q_FUNC_INFO
<< QString::number(this->ueCommunicationsSocket()->error())
<< this->ueCommunicationsSocket()->errorString(); // here i get semantic issue
} // if
and I am getting semantic issue warning code will never be executed. I am aware this is some dumb mistake and I am ready to get downvote(s), however, I cannot find mistake! Here is also a screenshot:
if(this->ueCommunicationsSocket()->bind(QHostAddress(data[0].toString()),
static_cast<quint16>(data[1].toInt())),
QAbstractSocket::ShareAddress)
is
if ( /*something */, QAbstractSocket::ShareAddress)
since AbstractSocket::SharedAddress is 0x1, this condition with a comma operator ! is always true, i.e. the else branch will never be executed.
I try to access a simple text file from a Qt-widget application with the QFile class for reading an writing. Reading the file line by line as a string works fine. But opening it ready to write fails. The following code checks if the file exists and tries to set the proper permissions, but in the end the file won't open.
Here is the failing piece of code:
#include "mainwindow.h"
#include <QApplication>
#include <QFile>
#include <QDebug>
int main(int argc, char *argv[]){
QApplication app(argc, argv);
MainWindow w;
w.show();
QFile file(":/test.dat");
qDebug() << "exists? " << file.exists();
qDebug() << "writable? " << file.isWritable();
qDebug() << "permissions before? " << file.permissions();
qDebug() << "permissions set? " << file.setPermissions(QFileDevice::WriteOther | QFileDevice::ReadOther);
qDebug() << "permissions after? " << file.permissions();
qDebug() << "opened? " << file.open(QIODevice::Append);
qDebug() << "errors? " << file.errorString();
qDebug() << "errnum? " << file.error();
QTextStream out(&file);
out << "something to append";
file.close();
return app.exec();
}
Qt returns this message:
exists? true
writable? false
permissions before? QFlags(0x4|0x40|0x400|0x4000)
permissions set? false
permissions after? QFlags(0x4|0x40|0x400|0x4000)
opened? false
errors? "Unknown error"
errnum? 5
QIODevice::write (QFile, ":/test.dat"): device not open
If I change the parameter in the open-function to QIODevice::ReadOnly the file is readable without problems, failing with QIODevice::WriteOnly. Why doesn't the same thing work for writing as well? Is it the permission? And why don't the permissions change after I called setPermissions? I run Qt as root on Ubuntu 14.04. And test.dat has full rights -rwxrwxrwx owned by user.
Can someone help?
Thanks!
The author is having Linux-related problem with writing to file created by console process with elevated privileges. I have fully reproduced the problem and when attempted to remove the file with:
vi \home\myuser\Documents\f.txt // create file like that from console
rm \home\myuser\Documents\f.txt // now try to remove it from console
I got "rm: remove write-protected regular file "\home\myuser\Documents\f.txt" and responded "yes" and then the code above shows after creating new file in the context of the program's process:
opened? true
exists? true
writable? true
permissions before? QFlags(0x4|0x20|0x40|0x200|0x400|0x2000|0x4000)
permissions set? true
permissions after? QFlags(0x4|0x20|0x40|0x200|0x400|0x2000|0x4000)
errors? "Unknown error"
errnum? 0
I run Qt Creator as root on Ubuntu 14.04.
It does not ensure the privileges of the program you run from it, I guess. UPDATE: make sure you run the program with appropriate permissions e.g. Root in this case.
I am building a telnet server app in Qt, and when I connect from a linux telnet client output looks great. For example, sending "A" << endl << "B" << endl << "C" to my console looks like:
A
B
C
Now when I connect from a Windows telnet client I see
A
B
C
obviously Qt's endl is sending only '\n'. Is there a SIMPLE solution to this? If I replace endl with "\r\n" do I mess up linux clients now? Do I have to force a flush too?
Here is actual code I am using to send to my telnet client:
QString block;
QTextStream out(&block, QIODevice::WriteOnly);
out << "Valid commands are: " << endl
<< " help Print this list" << endl
<< " version Print this version" << endl
<< " clientcount Show the number of active telnet clients" << endl
<< " logrotate Rotate the event log file" << endl
<< " shutdown Initiate shutdown secast" << endl
<< " quit Disconnect your telnet session" << endl
<< " stop Shutdown secast" << endl;
tcpSocketPtr->write(block.toUtf8());
You could simply drop the QTextStream and write the QString directly in here:
QString block = QString("Valid commands are: \n")
+ " help Print this list\n"
+ " version Print this version\n"
+ " clientcount Show the number of active telnet clients\n"
+ " logrotate Rotate the event log file\n"
+ " shutdown Initiate shutdown secast\n"
+ " quit Disconnect your telnet session\n"
+ " stop Shutdown secast\n";
tcpSocketPtr->write(block.toUtf8());
Based on your comment though, you seem to use some old DOS client (on Windows!) which expects "\r\n". In that case, I would send "\r\n" for that, but only the usual "\n" for Linux. It is a not so good practice to send carriage return as well on Linux, and not just line feed even though "\r\n" may seem to work on Linux.